Bugbear: Add Mutable Parameter fixes (#9682)

Part of #9366

Adds in fixes for B006 and B008, both relating to mutable parameter lint errors.

Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>

8 files changed, 58 insertions, 26 deletions

diff --git a/synapse/storage/database.py b/synapse/storage/database.py
index b302cd5786..fa15b0ce5b 100644
--- a/synapse/storage/database.py
+++ b/synapse/storage/database.py
@@ -900,7 +900,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
         desc: str = "simple_upsert",
         lock: bool = True,
     ) -> Optional[bool]:
@@ -927,6 +927,8 @@ class DatabasePool:
             Native upserts always return None. Emulated upserts return True if a
             new entry was created, False if an existing one was updated.
         """
+        insertion_values = insertion_values or {}
+
         attempts = 0
         while True:
             try:
@@ -964,7 +966,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
         lock: bool = True,
     ) -> Optional[bool]:
         """
@@ -982,6 +984,8 @@ class DatabasePool:
             Native upserts always return None. Emulated upserts return True if a
             new entry was created, False if an existing one was updated.
         """
+        insertion_values = insertion_values or {}
+
         if self.engine.can_native_upsert and table not in self._unsafe_to_upsert_tables:
             self.simple_upsert_txn_native_upsert(
                 txn, table, keyvalues, values, insertion_values=insertion_values
@@ -1003,7 +1007,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
         lock: bool = True,
     ) -> bool:
         """
@@ -1017,6 +1021,8 @@ class DatabasePool:
             Returns True if a new entry was created, False if an existing
             one was updated.
         """
+        insertion_values = insertion_values or {}
+
         # We need to lock the table :(, unless we're *really* careful
         if lock:
             self.engine.lock_table(txn, table)
@@ -1077,7 +1083,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
     ) -> None:
         """
         Use the native UPSERT functionality in recent PostgreSQL versions.
@@ -1090,7 +1096,7 @@ class DatabasePool:
         """
         allvalues = {}  # type: Dict[str, Any]
         allvalues.update(keyvalues)
-        allvalues.update(insertion_values)
+        allvalues.update(insertion_values or {})
 
         if not values:
             latter = "NOTHING"
@@ -1513,7 +1519,7 @@ class DatabasePool:
         column: str,
         iterable: Iterable[Any],
         retcols: Iterable[str],
-        keyvalues: Dict[str, Any] = {},
+        keyvalues: Optional[Dict[str, Any]] = None,
         desc: str = "simple_select_many_batch",
         batch_size: int = 100,
     ) -> List[Any]:
@@ -1531,6 +1537,8 @@ class DatabasePool:
             desc: description of the transaction, for logging and metrics
             batch_size: the number of rows for each select query
         """
+        keyvalues = keyvalues or {}
+
         results = []  # type: List[Dict[str, Any]]
 
         if not iterable:
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 98dac19a95..ad17123915 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -320,8 +320,8 @@ class PersistEventsStore:
         txn: LoggingTransaction,
         events_and_contexts: List[Tuple[EventBase, EventContext]],
         backfilled: bool,
-        state_delta_for_room: Dict[str, DeltaState] = {},
-        new_forward_extremeties: Dict[str, List[str]] = {},
+        state_delta_for_room: Optional[Dict[str, DeltaState]] = None,
+        new_forward_extremeties: Optional[Dict[str, List[str]]] = None,
     ):
         """Insert some number of room events into the necessary database tables.
 
@@ -342,6 +342,9 @@ class PersistEventsStore:
                 extremities.
 
         """
+        state_delta_for_room = state_delta_for_room or {}
+        new_forward_extremeties = new_forward_extremeties or {}
+
         all_events_and_contexts = events_and_contexts
 
         min_stream_order = events_and_contexts[0][0].internal_metadata.stream_ordering
diff --git a/synapse/storage/databases/main/group_server.py b/synapse/storage/databases/main/group_server.py
index 8f462dfc31..bd7826f4e9 100644
--- a/synapse/storage/databases/main/group_server.py
+++ b/synapse/storage/databases/main/group_server.py
@@ -1171,7 +1171,7 @@ class GroupServerStore(GroupServerWorkerStore):
         user_id: str,
         membership: str,
         is_admin: bool = False,
-        content: JsonDict = {},
+        content: Optional[JsonDict] = None,
         local_attestation: Optional[dict] = None,
         remote_attestation: Optional[dict] = None,
         is_publicised: bool = False,
@@ -1192,6 +1192,8 @@ class GroupServerStore(GroupServerWorkerStore):
             is_publicised: Whether this should be publicised.
         """
 
+        content = content or {}
+
         def _register_user_group_membership_txn(txn, next_id):
             # TODO: Upsert?
             self.db_pool.simple_delete_txn(
diff --git a/synapse/storage/databases/main/state.py b/synapse/storage/databases/main/state.py
index a7f371732f..93431efe00 100644
--- a/synapse/storage/databases/main/state.py
+++ b/synapse/storage/databases/main/state.py
@@ -190,7 +190,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
 
     # FIXME: how should this be cached?
     async def get_filtered_current_state_ids(
-        self, room_id: str, state_filter: StateFilter = StateFilter.all()
+        self, room_id: str, state_filter: Optional[StateFilter] = None
     ) -> StateMap[str]:
         """Get the current state event of a given type for a room based on the
         current_state_events table.  This may not be as up-to-date as the result
@@ -205,7 +205,9 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
             Map from type/state_key to event ID.
         """
 
-        where_clause, where_args = state_filter.make_sql_filter_clause()
+        where_clause, where_args = (
+            state_filter or StateFilter.all()
+        ).make_sql_filter_clause()
 
         if not where_clause:
             # We delegate to the cached version
diff --git a/synapse/storage/databases/state/bg_updates.py b/synapse/storage/databases/state/bg_updates.py
index 1fd333b707..75c09b3687 100644
--- a/synapse/storage/databases/state/bg_updates.py
+++ b/synapse/storage/databases/state/bg_updates.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import logging
+from typing import Optional
 
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import DatabasePool
@@ -73,8 +74,10 @@ class StateGroupBackgroundUpdateStore(SQLBaseStore):
             return count
 
     def _get_state_groups_from_groups_txn(
-        self, txn, groups, state_filter=StateFilter.all()
+        self, txn, groups, state_filter: Optional[StateFilter] = None
     ):
+        state_filter = state_filter or StateFilter.all()
+
         results = {group: {} for group in groups}
 
         where_clause, where_args = state_filter.make_sql_filter_clause()
diff --git a/synapse/storage/databases/state/store.py b/synapse/storage/databases/state/store.py
index 97ec65f757..dfcf89d91c 100644
--- a/synapse/storage/databases/state/store.py
+++ b/synapse/storage/databases/state/store.py
@@ -15,7 +15,7 @@
 
 import logging
 from collections import namedtuple
-from typing import Dict, Iterable, List, Set, Tuple
+from typing import Dict, Iterable, List, Optional, Set, Tuple
 
 from synapse.api.constants import EventTypes
 from synapse.storage._base import SQLBaseStore
@@ -210,7 +210,7 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         return state_filter.filter_state(state_dict_ids), not missing_types
 
     async def _get_state_for_groups(
-        self, groups: Iterable[int], state_filter: StateFilter = StateFilter.all()
+        self, groups: Iterable[int], state_filter: Optional[StateFilter] = None
     ) -> Dict[int, MutableStateMap[str]]:
         """Gets the state at each of a list of state groups, optionally
         filtering by type/state_key
@@ -223,6 +223,7 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         Returns:
             Dict of state group to state map.
         """
+        state_filter = state_filter or StateFilter.all()
 
         member_filter, non_member_filter = state_filter.get_member_split()
 
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 2e277a21c4..c1c147c62a 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -449,7 +449,7 @@ class StateGroupStorage:
         return self.stores.state._get_state_groups_from_groups(groups, state_filter)
 
     async def get_state_for_events(
-        self, event_ids: Iterable[str], state_filter: StateFilter = StateFilter.all()
+        self, event_ids: Iterable[str], state_filter: Optional[StateFilter] = None
     ) -> Dict[str, StateMap[EventBase]]:
         """Given a list of event_ids and type tuples, return a list of state
         dicts for each event.
@@ -465,7 +465,7 @@ class StateGroupStorage:
 
         groups = set(event_to_groups.values())
         group_to_state = await self.stores.state._get_state_for_groups(
-            groups, state_filter
+            groups, state_filter or StateFilter.all()
         )
 
         state_event_map = await self.stores.main.get_events(
@@ -485,7 +485,7 @@ class StateGroupStorage:
         return {event: event_to_state[event] for event in event_ids}
 
     async def get_state_ids_for_events(
-        self, event_ids: Iterable[str], state_filter: StateFilter = StateFilter.all()
+        self, event_ids: Iterable[str], state_filter: Optional[StateFilter] = None
     ) -> Dict[str, StateMap[str]]:
         """
         Get the state dicts corresponding to a list of events, containing the event_ids
@@ -502,7 +502,7 @@ class StateGroupStorage:
 
         groups = set(event_to_groups.values())
         group_to_state = await self.stores.state._get_state_for_groups(
-            groups, state_filter
+            groups, state_filter or StateFilter.all()
         )
 
         event_to_state = {
@@ -513,7 +513,7 @@ class StateGroupStorage:
         return {event: event_to_state[event] for event in event_ids}
 
     async def get_state_for_event(
-        self, event_id: str, state_filter: StateFilter = StateFilter.all()
+        self, event_id: str, state_filter: Optional[StateFilter] = None
     ) -> StateMap[EventBase]:
         """
         Get the state dict corresponding to a particular event
@@ -525,11 +525,13 @@ class StateGroupStorage:
         Returns:
             A dict from (type, state_key) -> state_event
         """
-        state_map = await self.get_state_for_events([event_id], state_filter)
+        state_map = await self.get_state_for_events(
+            [event_id], state_filter or StateFilter.all()
+        )
         return state_map[event_id]
 
     async def get_state_ids_for_event(
-        self, event_id: str, state_filter: StateFilter = StateFilter.all()
+        self, event_id: str, state_filter: Optional[StateFilter] = None
     ) -> StateMap[str]:
         """
         Get the state dict corresponding to a particular event
@@ -541,11 +543,13 @@ class StateGroupStorage:
         Returns:
             A dict from (type, state_key) -> state_event
         """
-        state_map = await self.get_state_ids_for_events([event_id], state_filter)
+        state_map = await self.get_state_ids_for_events(
+            [event_id], state_filter or StateFilter.all()
+        )
         return state_map[event_id]
 
     def _get_state_for_groups(
-        self, groups: Iterable[int], state_filter: StateFilter = StateFilter.all()
+        self, groups: Iterable[int], state_filter: Optional[StateFilter] = None
     ) -> Awaitable[Dict[int, MutableStateMap[str]]]:
         """Gets the state at each of a list of state groups, optionally
         filtering by type/state_key
@@ -558,7 +562,9 @@ class StateGroupStorage:
         Returns:
             Dict of state group to state map.
         """
-        return self.stores.state._get_state_for_groups(groups, state_filter)
+        return self.stores.state._get_state_for_groups(
+            groups, state_filter or StateFilter.all()
+        )
 
     async def store_state_group(
         self,
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py
index d4643c4fdf..32d6cc16b9 100644
--- a/synapse/storage/util/id_generators.py
+++ b/synapse/storage/util/id_generators.py
@@ -17,7 +17,7 @@ import logging
 import threading
 from collections import OrderedDict
 from contextlib import contextmanager
-from typing import Dict, List, Optional, Set, Tuple, Union
+from typing import Dict, Iterable, List, Optional, Set, Tuple, Union
 
 import attr
 
@@ -91,7 +91,14 @@ class StreamIdGenerator:
             # ... persist event ...
     """
 
-    def __init__(self, db_conn, table, column, extra_tables=[], step=1):
+    def __init__(
+        self,
+        db_conn,
+        table,
+        column,
+        extra_tables: Iterable[Tuple[str, str]] = (),
+        step=1,
+    ):
         assert step != 0
         self._lock = threading.Lock()
         self._step = step